The goal of the Analytical Core is to support SWEHSC investigators in the identification, characterization and measurement of chemical substances. This is done primarily through the use of mass spectrometry and related chromatographic and spectroscopic methods. Dr. Liebler oversees the operation of the Analytical Core Laboratory, Dr. Thomas McClure serves as the Facility Manager, and Ms. Sherry Daugherty, B.S., is responsible for conducting GC-MS and HPLC analyses. The Analytical Core Laboratory (800 sq. ft.) is located in the College of Pharmacy. While the Core was set up under the auspices of the SWEHSC, it has recently been decided to integrate the operation of the Core with the Arizona Cancer Center (ACC). Dr. Liebler will continue to direct the facility, the current Core personnel will be joined by a second Research Technician (funded by the ACC), and the user base will be expanded by about 50%. The major pieces of equipment that comprise the Core are a TSQ7000 triple quadrupole MS with electrospray and chemical ionization, a Hewlett Packard 1050 HPLC with autosampler, and a GC-MS (Finnegan benchtop MS, CarloErba 8000 series GC). In addition to GC-MS analyses and LC-MS analyses, methods development is provided (60 total projects in the reporting period). The targets of most of the LC-MS analyses appear to be small molecules - metabolites, adducts, synthetic compounds. However, several more ambitious projects including peptide sequencing projects have also been completed. In the period 1994-97, a total of 1865 LC-MS analyses and 662 GC-MS analyses were performed for SWEHSC investigators; this represents about 60% of the total usage of the facility. Because the instruments were bought with funds from several sources, non-SWEHSC investigators are given access to the instruments with a lower priority than SWEHSC investigators. Methods development is not performed for non-SWEHSC members. The recent installation of user friendly software that can control the TSQ7000 has given users direct access to the machine and nearly doubled the yearly total number of analyses. The current lag time for getting onto the TSQ is about 30 days. A total of 17 Center members utilized the Analytical Core; three major users (Drs. Sipes, Liebler and Witten) accounted for 50% or more of the usage in each category.